Abstract.
The production of PHAs (polyhydroxyalkanoates) and especially its monomer PHB (polyhydroxybutyrate), is of interest because its high added value. It would be interest the industrial obtaining using some microorganisms, either with pure cultures or microbial consortia growing in different types of substrates. PHAs products are of potential interest for their similar properties to various synthetic polymers such as polypropylene thermoplastics. The PHB also have the advantage that they can be synthesized and degraded by various microorganisms, because its degradability some thermal and miscibility properties have been studied. Among the microorganism that capable to synthesize PHB are phototrophic mixed cultures. Despite its great advantages over synthetic materials, the cost of production by microbial sources is still far
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superior compare to synthetic plastics. In order to reduce the cost it’s necessary research and develops competitive production processes. In the present work it was determined and compared the production of PHB with three phototrophic microbial consortia.
The culture known as C4 produced the most weight PHB, reaching a maximum accumulation up to 44 % of cell dry weight. PHB produced by this consortium provided an average of 1313m /z, of molecular mass slightly superior compare to commercial PHB. This phototrophic consortium named C4 was characterized to determinate, its microbial composition resulting in 60% of polymer producing populations.
While the polymer obtained by the consortium C2 is highly crystalline this gives a greater resistance similar to polyesters. However, the accumulation rate was about 26 %, with only 34 % of the total population as producers of PHB .